1 //===- ArchiveWriter.cpp - ar File Format implementation --------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the writeArchive function.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Object/ArchiveWriter.h"
15 #include "llvm/ADT/ArrayRef.h"
16 #include "llvm/ADT/StringRef.h"
17 #include "llvm/IR/LLVMContext.h"
18 #include "llvm/Object/Archive.h"
19 #include "llvm/Object/ObjectFile.h"
20 #include "llvm/Object/SymbolicFile.h"
21 #include "llvm/Support/EndianStream.h"
22 #include "llvm/Support/Errc.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/Format.h"
25 #include "llvm/Support/Path.h"
26 #include "llvm/Support/ToolOutputFile.h"
27 #include "llvm/Support/raw_ostream.h"
29 #if !defined(_MSC_VER) && !defined(__MINGW32__)
37 NewArchiveMember::NewArchiveMember(MemoryBufferRef BufRef)
38 : Buf(MemoryBuffer::getMemBuffer(BufRef, false)) {}
40 Expected<NewArchiveMember>
41 NewArchiveMember::getOldMember(const object::Archive::Child &OldMember,
43 ErrorOr<llvm::MemoryBufferRef> BufOrErr = OldMember.getMemoryBufferRef();
45 return errorCodeToError(BufOrErr.getError());
48 M.Buf = MemoryBuffer::getMemBuffer(*BufOrErr, false);
50 M.ModTime = OldMember.getLastModified();
51 M.UID = OldMember.getUID();
52 M.GID = OldMember.getGID();
53 M.Perms = OldMember.getAccessMode();
58 Expected<NewArchiveMember> NewArchiveMember::getFile(StringRef FileName,
60 sys::fs::file_status Status;
62 if (auto EC = sys::fs::openFileForRead(FileName, FD))
63 return errorCodeToError(EC);
66 if (auto EC = sys::fs::status(FD, Status))
67 return errorCodeToError(EC);
69 // Opening a directory doesn't make sense. Let it fail.
70 // Linux cannot open directories with open(2), although
71 // cygwin and *bsd can.
72 if (Status.type() == sys::fs::file_type::directory_file)
73 return errorCodeToError(make_error_code(errc::is_a_directory));
75 ErrorOr<std::unique_ptr<MemoryBuffer>> MemberBufferOrErr =
76 MemoryBuffer::getOpenFile(FD, FileName, Status.getSize(), false);
77 if (!MemberBufferOrErr)
78 return errorCodeToError(MemberBufferOrErr.getError());
81 return errorCodeToError(std::error_code(errno, std::generic_category()));
84 M.Buf = std::move(*MemberBufferOrErr);
86 M.ModTime = Status.getLastModificationTime();
87 M.UID = Status.getUser();
88 M.GID = Status.getGroup();
89 M.Perms = Status.permissions();
95 static void printWithSpacePadding(raw_fd_ostream &OS, T Data, unsigned Size,
96 bool MayTruncate = false) {
97 uint64_t OldPos = OS.tell();
99 unsigned SizeSoFar = OS.tell() - OldPos;
100 if (Size > SizeSoFar) {
101 OS.indent(Size - SizeSoFar);
102 } else if (Size < SizeSoFar) {
103 assert(MayTruncate && "Data doesn't fit in Size");
104 // Some of the data this is used for (like UID) can be larger than the
105 // space available in the archive format. Truncate in that case.
106 OS.seek(OldPos + Size);
110 static void print32(raw_ostream &Out, object::Archive::Kind Kind,
112 if (Kind == object::Archive::K_GNU)
113 support::endian::Writer<support::big>(Out).write(Val);
115 support::endian::Writer<support::little>(Out).write(Val);
118 static void printRestOfMemberHeader(raw_fd_ostream &Out,
119 const sys::TimeValue &ModTime, unsigned UID,
120 unsigned GID, unsigned Perms,
122 printWithSpacePadding(Out, ModTime.toEpochTime(), 12);
123 printWithSpacePadding(Out, UID, 6, true);
124 printWithSpacePadding(Out, GID, 6, true);
125 printWithSpacePadding(Out, format("%o", Perms), 8);
126 printWithSpacePadding(Out, Size, 10);
130 static void printGNUSmallMemberHeader(raw_fd_ostream &Out, StringRef Name,
131 const sys::TimeValue &ModTime,
132 unsigned UID, unsigned GID,
133 unsigned Perms, unsigned Size) {
134 printWithSpacePadding(Out, Twine(Name) + "/", 16);
135 printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
138 static void printBSDMemberHeader(raw_fd_ostream &Out, StringRef Name,
139 const sys::TimeValue &ModTime, unsigned UID,
140 unsigned GID, unsigned Perms, unsigned Size) {
141 uint64_t PosAfterHeader = Out.tell() + 60 + Name.size();
142 // Pad so that even 64 bit object files are aligned.
143 unsigned Pad = OffsetToAlignment(PosAfterHeader, 8);
144 unsigned NameWithPadding = Name.size() + Pad;
145 printWithSpacePadding(Out, Twine("#1/") + Twine(NameWithPadding), 16);
146 printRestOfMemberHeader(Out, ModTime, UID, GID, Perms,
147 NameWithPadding + Size);
149 assert(PosAfterHeader == Out.tell());
151 Out.write(uint8_t(0));
154 static bool useStringTable(bool Thin, StringRef Name) {
155 return Thin || Name.size() >= 16;
159 printMemberHeader(raw_fd_ostream &Out, object::Archive::Kind Kind, bool Thin,
161 std::vector<unsigned>::iterator &StringMapIndexIter,
162 const sys::TimeValue &ModTime, unsigned UID, unsigned GID,
163 unsigned Perms, unsigned Size) {
164 if (Kind == object::Archive::K_BSD)
165 return printBSDMemberHeader(Out, Name, ModTime, UID, GID, Perms, Size);
166 if (!useStringTable(Thin, Name))
167 return printGNUSmallMemberHeader(Out, Name, ModTime, UID, GID, Perms, Size);
169 printWithSpacePadding(Out, *StringMapIndexIter++, 15);
170 printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
173 // Compute the relative path from From to To.
174 static std::string computeRelativePath(StringRef From, StringRef To) {
175 if (sys::path::is_absolute(From) || sys::path::is_absolute(To))
178 StringRef DirFrom = sys::path::parent_path(From);
179 auto FromI = sys::path::begin(DirFrom);
180 auto ToI = sys::path::begin(To);
181 while (*FromI == *ToI) {
186 SmallString<128> Relative;
187 for (auto FromE = sys::path::end(DirFrom); FromI != FromE; ++FromI)
188 sys::path::append(Relative, "..");
190 for (auto ToE = sys::path::end(To); ToI != ToE; ++ToI)
191 sys::path::append(Relative, *ToI);
193 return Relative.str();
196 static void writeStringTable(raw_fd_ostream &Out, StringRef ArcName,
197 ArrayRef<NewArchiveMember> Members,
198 std::vector<unsigned> &StringMapIndexes,
200 unsigned StartOffset = 0;
201 for (const NewArchiveMember &M : Members) {
202 StringRef Path = M.Buf->getBufferIdentifier();
203 StringRef Name = sys::path::filename(Path);
204 if (!useStringTable(Thin, Name))
206 if (StartOffset == 0) {
207 printWithSpacePadding(Out, "//", 58);
209 StartOffset = Out.tell();
211 StringMapIndexes.push_back(Out.tell() - StartOffset);
214 Out << computeRelativePath(ArcName, Path);
220 if (StartOffset == 0)
224 int Pos = Out.tell();
225 Out.seek(StartOffset - 12);
226 printWithSpacePadding(Out, Pos - StartOffset, 10);
230 static sys::TimeValue now(bool Deterministic) {
232 return sys::TimeValue::now();
238 // Returns the offset of the first reference to a member offset.
239 static ErrorOr<unsigned>
240 writeSymbolTable(raw_fd_ostream &Out, object::Archive::Kind Kind,
241 ArrayRef<NewArchiveMember> Members,
242 std::vector<unsigned> &MemberOffsetRefs, bool Deterministic) {
243 unsigned HeaderStartOffset = 0;
244 unsigned BodyStartOffset = 0;
245 SmallString<128> NameBuf;
246 raw_svector_ostream NameOS(NameBuf);
248 for (unsigned MemberNum = 0, N = Members.size(); MemberNum < N; ++MemberNum) {
249 MemoryBufferRef MemberBuffer = Members[MemberNum].Buf->getMemBufferRef();
250 Expected<std::unique_ptr<object::SymbolicFile>> ObjOrErr =
251 object::SymbolicFile::createSymbolicFile(
252 MemberBuffer, sys::fs::file_magic::unknown, &Context);
254 // FIXME: check only for "not an object file" errors.
255 consumeError(ObjOrErr.takeError());
258 object::SymbolicFile &Obj = *ObjOrErr.get();
260 if (!HeaderStartOffset) {
261 HeaderStartOffset = Out.tell();
262 if (Kind == object::Archive::K_GNU)
263 printGNUSmallMemberHeader(Out, "", now(Deterministic), 0, 0, 0, 0);
265 printBSDMemberHeader(Out, "__.SYMDEF", now(Deterministic), 0, 0, 0, 0);
266 BodyStartOffset = Out.tell();
267 print32(Out, Kind, 0); // number of entries or bytes
270 for (const object::BasicSymbolRef &S : Obj.symbols()) {
271 uint32_t Symflags = S.getFlags();
272 if (Symflags & object::SymbolRef::SF_FormatSpecific)
274 if (!(Symflags & object::SymbolRef::SF_Global))
276 if (Symflags & object::SymbolRef::SF_Undefined)
279 unsigned NameOffset = NameOS.tell();
280 if (auto EC = S.printName(NameOS))
283 MemberOffsetRefs.push_back(MemberNum);
284 if (Kind == object::Archive::K_BSD)
285 print32(Out, Kind, NameOffset);
286 print32(Out, Kind, 0); // member offset
290 if (HeaderStartOffset == 0)
293 StringRef StringTable = NameOS.str();
294 if (Kind == object::Archive::K_BSD)
295 print32(Out, Kind, StringTable.size()); // byte count of the string table
298 // ld64 requires the next member header to start at an offset that is
300 unsigned Pad = OffsetToAlignment(Out.tell(), 4);
302 Out.write(uint8_t(0));
304 // Patch up the size of the symbol table now that we know how big it is.
305 unsigned Pos = Out.tell();
306 const unsigned MemberHeaderSize = 60;
307 Out.seek(HeaderStartOffset + 48); // offset of the size field.
308 printWithSpacePadding(Out, Pos - MemberHeaderSize - HeaderStartOffset, 10);
310 // Patch up the number of symbols.
311 Out.seek(BodyStartOffset);
312 unsigned NumSyms = MemberOffsetRefs.size();
313 if (Kind == object::Archive::K_GNU)
314 print32(Out, Kind, NumSyms);
316 print32(Out, Kind, NumSyms * 8);
319 return BodyStartOffset + 4;
322 std::pair<StringRef, std::error_code>
323 llvm::writeArchive(StringRef ArcName,
324 std::vector<NewArchiveMember> &NewMembers,
325 bool WriteSymtab, object::Archive::Kind Kind,
326 bool Deterministic, bool Thin,
327 std::unique_ptr<MemoryBuffer> OldArchiveBuf) {
328 assert((!Thin || Kind == object::Archive::K_GNU) &&
329 "Only the gnu format has a thin mode");
330 SmallString<128> TmpArchive;
332 if (auto EC = sys::fs::createUniqueFile(ArcName + ".temp-archive-%%%%%%%.a",
333 TmpArchiveFD, TmpArchive))
334 return std::make_pair(ArcName, EC);
336 tool_output_file Output(TmpArchive, TmpArchiveFD);
337 raw_fd_ostream &Out = Output.os();
343 std::vector<unsigned> MemberOffsetRefs;
345 std::vector<std::unique_ptr<MemoryBuffer>> Buffers;
346 std::vector<MemoryBufferRef> Members;
347 std::vector<sys::fs::file_status> NewMemberStatus;
349 unsigned MemberReferenceOffset = 0;
351 ErrorOr<unsigned> MemberReferenceOffsetOrErr = writeSymbolTable(
352 Out, Kind, NewMembers, MemberOffsetRefs, Deterministic);
353 if (auto EC = MemberReferenceOffsetOrErr.getError())
354 return std::make_pair(ArcName, EC);
355 MemberReferenceOffset = MemberReferenceOffsetOrErr.get();
358 std::vector<unsigned> StringMapIndexes;
359 if (Kind != object::Archive::K_BSD)
360 writeStringTable(Out, ArcName, NewMembers, StringMapIndexes, Thin);
362 std::vector<unsigned>::iterator StringMapIndexIter = StringMapIndexes.begin();
363 std::vector<unsigned> MemberOffset;
364 for (const NewArchiveMember &M : NewMembers) {
365 MemoryBufferRef File = M.Buf->getMemBufferRef();
367 unsigned Pos = Out.tell();
368 MemberOffset.push_back(Pos);
370 printMemberHeader(Out, Kind, Thin,
371 sys::path::filename(M.Buf->getBufferIdentifier()),
372 StringMapIndexIter, M.ModTime, M.UID, M.GID, M.Perms,
373 M.Buf->getBufferSize());
376 Out << File.getBuffer();
382 if (MemberReferenceOffset) {
383 Out.seek(MemberReferenceOffset);
384 for (unsigned MemberNum : MemberOffsetRefs) {
385 if (Kind == object::Archive::K_BSD)
386 Out.seek(Out.tell() + 4); // skip over the string offset
387 print32(Out, Kind, MemberOffset[MemberNum]);
394 // At this point, we no longer need whatever backing memory
395 // was used to generate the NewMembers. On Windows, this buffer
396 // could be a mapped view of the file we want to replace (if
397 // we're updating an existing archive, say). In that case, the
398 // rename would still succeed, but it would leave behind a
399 // temporary file (actually the original file renamed) because
400 // a file cannot be deleted while there's a handle open on it,
401 // only renamed. So by freeing this buffer, this ensures that
402 // the last open handle on the destination file, if any, is
403 // closed before we attempt to rename.
404 OldArchiveBuf.reset();
406 sys::fs::rename(TmpArchive, ArcName);
407 return std::make_pair("", std::error_code());